1. Field of the Invention
The present invention relates to a boosting circuit, and more particularly, to a boosting circuit capable of preventing giving stress to a cell due to a high voltage applied to word lines of the cell, preventing unnecessary consumption of current and securing the read-out margin, wherein a first boosting means and a second boosting means are precharged with a first potential in a standby mode, and the cell current of the flash memory cell is varied according to a boosting potential of the first boosting means in a read-out mode, whereby the output of a flash memory cell sensing circuit unit is changed and the second boosting means is thus boosted to a third potential or a fourth potential.
2. Background of the Related Art
In order to read out the status of cells in flash memory devices for low voltage, it is required that a voltage higher than the operating voltage be applied to the word lines of the cells. For this, a method of boosting the operating voltage to produce a voltage higher than the operating voltage has been employed. If the operating voltage is boosted twice when the operating supply power of the flash memory cell for low voltage is about 1.8˜2.4V, the boosting voltage is about 4˜5.4V or higher. If the boosting voltage of over 5.5V is applied to the word lines, however, it is almost same to a program verification voltage of about 6V. Due to this, there are problems that the read-out margin could not be secured and the lifetime of the cell is shortened due to stress applied thereto.